1. Field of the Invention
The present invention relates to streaming multimedia content, and, more particularly, to distributing the function among clients in a client-server relationship.
2. Description of the Related Art
Video on demand (VoD) services include streaming service provided on the Internet, VoD service provided through cable TV broadcasting, etc. A currently provided VoD service usually has a transmission rate of no more than several hundreds kilobits per second (kbps) to 1 megabit per second (Mbps). However, a streaming service having a transmission rate of several Mbps is expected to gain widespread adoption by virtue of the broadband residential access network and the demand for high quality content.
In a typical streaming service provided through the Internet, when a user selects particular content, it is necessary that the content should be first buffered through an application program running on the UMD before being displayed on the UMD.
In a typical streaming service, although the particular content is delivered to a UMD from a content server in an end-to-end form, frequently accessed contents are previously placed up to a network edge in the case where a content delivery network (CDN), a cache server, etc. are employed. It is accordingly possible to prevent service failure that might otherwise occur due to overload of the content server and transmission delay through a network.
Among the recent developments in subscriber multimedia devices are high capability computers, high capacity storage media, personal video recorders (PVRs), etc. Consequently, in some Internet VoD services, when a user computer accesses a network, entire contents having been updated in a content server are automatically downloaded by an application program and stored at the user computer, enabling the user to select from among the stored contents for subsequent display or presentation.
However, the typical streaming service suffers delay caused by initial buffering and buffering when contents are skipped in reproduction.
Also, a content storage type VoD service requires a UMD having a large-capacity storage medium. In addition, since the device stores potentially a large amount content, it becomes necessary to implement the device with the additional protection capability.